The current study tested whether rates of externalizing disorders are higher in individuals with PAE than in COA. Six individual meta-analyses were performed: three estimating the effect sizes of ADHD, CD, and ODD in those with PAE compared to unexposed individuals, and another three estimating the effect sizes of the same disorders in COA compared to those with no family history of alcohol dependence. These analyses tested the hypotheses that rates of externalizing disorders are increased both in PAE and in COA. The novel analyses of this study were the subsequent comparisons of effect sizes between PAE and COA within each disorder, including a comparison of rates between PAE children (confirmed alcohol-exposed pregnancy) vs. offspring of (confirmed) AD mothers. These analyses tested the hypothesis that confirmed alcohol-exposed pregnancies increase the risk for externalizing disorders beyond that of heritable factors associated with confirmed maternal (or paternal) alcohol dependence. Notably, if the risk for an externalizing disorder is greater in PAE (maternal alcohol dependence likely but undocumented) than in COA (drinking during pregnancy likely but undocumented), it would provide compelling, novel evidence that the etiology of that disorder is attributable to the prenatal alcohol exposure.
